Yes, this reason is airlines trying to make more money through customer segmentation.
I'm perfectly fine with sabotaging their efforts in this regard.
Are you also fine with making it more expensive for other people to fly, for your convenience?
How about file sharing to sabotage the efforts of authors, musicians, etc. to "make more money"?
I'm not saying your position is wrong -- just asking whether it's consistent.
In any case, promoting the use of self-defeating strategies is either foolish or evil. Either you're foolish because you don't realize you're going to lose use of the loophole yourself, or you're evil because you're deliberately creating a tragedy of the commons, destroying multiple sources of value for multiple parties. (When the fares or authors go away, everybody loses, not just the airlines or authors.)
If you find an anti-inductive loophole, for heaven's sake don't talk about it.
The first rule of anti-inductive loophole club is that you do not talk about anti-inductive loophole club.
Again, what is the argument that shows that people are going to be worse off if airlines are prevented from setting this kind of price?
I don't see much analogy with software piracy and so on, since this would be more like sneaking onto a flight without buying a ticket. But even in the case of piracy, while it is clear that the author suffers in comparison to that very person paying, it is not clear that the author overall suffers from the existence of piracy. For example, it is quite likely that Microsoft has overall profited from piracy of Windows, since without it they would never have established their monopoly. Some open source operating system would have the monopoly instead.
I was going to wait to post this for reasons, but realized that was pretty dumb when the difference of a few weeks could literally save people hundreds, if not thousands of collective dollars.
If you fly regularly (or at all), you may already know about this method of saving money. The method is quite simple: instead of buying a round-trip ticket from the airline or reseller, you hunt down much cheaper one-way flights with layovers at your destination and/or your point of origin. Skiplagged is a service that will do this automatically for you, and has been in the news recently because the creator was sued by United Airlines and Orbitz. While Skiplagged will allow you to click-through to purchase the one-way ticket to your destination, they have broken or disabled the functionality of the redirect to the one-way ticket back (possibly in order to raise more funds for their legal defense). However, finding the return flight manually is fairly easy as the provide all the information to filter for it on other websites (time, airline, etc). I personally have benefited from this - I am flying to Texas from Southern California soon, and instead of a round-trip ticket which would cost me about $450, I spent ~$180 on two one-way tickets (with the return flight being the "layover" at my point-of-origin). These are, perhaps, larger than usual savings; I think 20-25% is more common, but even then it's a fairly significant amount of money.
Relevant warnings by gwillen:
Additionally, you should do all of your airline/hotel/etc shopping using whatever private browsing mode your web browser has. This will often let you purchase the exact same product for a cheaper price.
That is all.